Radio Detection of Extrasolar Planets: Present and Future Prospects
Abstract
By virtue of their planetary-scale magnetic fields, the Earth and all of the gas giants in our solar system possess solar-wind deformed magnetospheres. The magnetic polar regions of these ``magnetic planets'' produce intense, auroral-related radio emission from solar-wind powered electron currents.
We describe a combined theoretical and observational program designed to test the extent to which auroral radio emission from the known extrasolar planets may be detectable over interstellar distances. Various forms of a radiometric Bode's Law have been developed to describe the dependence of auroral radio emission upon a planet's distance from the Sun and its magnetic moment. A typical form of the radiometric Bode's Law has been applied to the current census of extrasolar planets. We find that the predicted median radio emission levels of the known extrasolar planets lies below current radio telescope detection limits such as the Very Large Array (VLA) and the Giant Metrewave Radio Telescope (GMRT) but that peak auroral radio emission levels lie close to the limit of detectability, under favorable conditions. Such planets might become detectable by future, larger instruments such as the Long Wavelength Array (LWA) and the Square Kilometer Array (SKA). We are also conducting a systematic effort to search for radio emission in low radio frequency images acquired with the VLA. The current limits set by the VLA are approaching, but do not yet provide strong constraints on, the predictions of the model. Basic research in radio astronomy at the Naval Research Laboratory is supported by the Office of Naval Research.- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AAS...20513508L